Oracle8i SQL Reference Release 2 (8.1.6) A76989-01 |
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SQL Statements (continued), 16 of 17
storage_clause: See "storage_clause".
To bring a rollback segment online or offline, to change its storage characteristics, or to shrink it to an optimal or specified size.
For information on creating a rollback segment, see "CREATE ROLLBACK SEGMENT".
You must have ALTER ROLLBACK SEGMENT
system privilege.
rollback_segment |
specifies the name of an existing rollback segment. |
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brings the rollback segment online. When you create a rollback segment, it is initially offline and not available for transactions. This clause brings the rollback segment online, making it available for transactions by your instance. You can also bring a rollback segment online when you start your instance with the initialization parameter |
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takes the rollback segment offline.
Once the rollback segment is offline, it can be brought online by any instance. |
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To see whether a rollback segment is online or offline, query the data dictionary view
Restriction: You cannot take the See Also: Oracle8i Administrator's Guide for more information on making rollback segments available and unavailable. |
storage_clause |
changes the rollback segment's storage characteristics. See the "storage_clause" for syntax and additional information.
Restriction: You cannot change the values of the |
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attempts to shrink the rollback segment to an optimal or specified size. The success and amount of shrinkage depend on the available free space in the rollback segment and how active transactions are holding space in the rollback segment. The value of integer is in bytes, unless you specify K or M for kilobytes or megabytes.
If you do not specify |
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Regardless of whether you specify TO integer:
To determine the actual size of a rollback segment after attempting to shrink it, query the Restriction: For a parallel server, you can shrink only rollback segments that are online to your instance. |
This statement brings the rollback segment RSONE
online:
ALTER ROLLBACK SEGMENT rsone ONLINE;
This statement changes the STORAGE
parameters for RSONE
:
ALTER ROLLBACK SEGMENT rsone STORAGE (NEXT 1000 MAXEXTENTS 20);
This statement attempts to resize a rollback segment to 100 megabytes:
ALTER ROLLBACK SEGMENT rsone SHRINK TO 100 M;
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